JP2009163580A - Personal authentication device - Google Patents

Abstract

Provided is a personal authentication device in which authentication performance does not deteriorate even if authentication is performed with a finger rotated with a reasonable device scale and processing time using a single imaging unit.
A light source unit 2 that emits light to a finger set in a predetermined unit, and an imaging unit 6 that captures an image of the finger with light reflected from the finger by the light emitted from the light source unit 2 are provided. In the personal authentication device that authenticates whether or not the person is the person based on the image picked up by the image pickup unit 6, the plurality of light control units 3 that reflect or transmit the light emitted from the light source unit 2, and the position of the finger to be imaged And a control unit 11 that switches the plurality of dimming units 3 to a reflective or transmissive state, and the light obtained through the dimming unit 3 that is switched to the reflective or transmissive state by the control unit 11 Based on the image picked up by (1), it is authenticated whether or not the user is the person.
[Selection] Figure 8

Description

  The present invention relates to a personal authentication device, and more particularly to a personal authentication device that authenticates an individual using a finger vein pattern image or a fingerprint pattern image as biometric information.

  In a conventional personal authentication device using a finger vein pattern image or a fingerprint pattern image based on biometric information, light is emitted from a light source to a finger, and an image of the finger vein pattern or fingerprint pattern is captured by an imaging unit. Then, the feature information obtained from the finger vein pattern image or fingerprint pattern image captured at the time of authentication is compared with the feature information obtained from the finger vein pattern image or fingerprint pattern image previously captured at the time of biometric information registration. In this way, personal authentication is performed.

  As a technique related to personal authentication, in Patent Document 1, a finger tip portion mounting base provided with a fingertip guide is provided in the personal authentication device so that it can slide toward the finger base portion mounting base along the inner wall surface of the apparatus main body. Thus, a technique for accurately detecting a finger vein pattern in consideration of the length of a finger when performing authentication is described.

  Patent Document 2 also provides a subject holding unit that can hold the surface of a fingerprint in a non-contact state, and obtains a fingerprint image corresponding to the fingerprint by imaging light from a light source that passes through the fingerprint of the subject. Thus, a technique that can acquire a stable fingerprint image without being affected by the surface state of the fingerprint is described.

  However, in these conventional technologies, when placing a finger at the time of registration and the way of placing the finger at the time of authentication are different, if only one of the registration or authentication is placed with the finger rotated, There is a problem in that the ratio of the areas where the fingers coincide is small in the image at the time of registration and the image at the time of authentication, and the authentication performance deteriorates.

  Therefore, in Patent Document 3, in order to prevent performance degradation due to finger rotation, two sets of optical units (light source and imaging unit) are provided to capture images of a plurality of finger regions, or one set of optical units. A technique is described in which images of a plurality of regions of a finger are picked up by moving a part to prevent performance degradation even when the finger is placed in a rotated state.

JP 2007-58643 A JP 2003-85538 A JP 2006-197981 A

  However, the apparatus including two sets of optical units has a problem that the scale of the entire apparatus becomes large. In the apparatus that moves one set of optical units, extra processing is required to move the optical units. There is a problem that it takes time.

  An object of the present invention is to provide a personal authentication device in which authentication performance does not deteriorate even if authentication is performed with a finger rotated with a reasonable device scale and processing time using one imaging unit.

  In order to achieve the above object, the personal authentication device of the present invention includes an irradiating unit that irradiates light on a finger set in a predetermined unit, and light emitted from the irradiating unit by light reflected from the finger. A personal authentication device that authenticates whether or not the person is based on the image picked up by the image pickup unit, and that reflects or transmits light emitted by the irradiating means. A dimming unit and a switching control unit that switches a plurality of the dimming units to a reflective or transmissive state according to the position of a finger to be imaged, and the switching control unit is switched to a reflective or transmissive state. Based on the image captured by the light obtained through the light control unit, it can be configured to authenticate whether or not the user is the person.

  A storage unit that stores the number of successful authentications associated with the image according to the position of the finger, and that corresponds to the position of the finger based on the number of successes stored in the storage unit; It can be configured to authenticate using an image.

  According to the present invention, it is possible to provide a personal authentication device in which authentication performance does not deteriorate even when authentication is performed with a finger rotated with a reasonable device scale and processing time using one imaging unit.

  Next, the best mode for carrying out the present invention will be described based on the following embodiments with reference to the drawings.

  FIG. 8 is a block diagram illustrating a configuration example of a finger vein authentication device 50 as an example of a personal authentication device.

  The finger vein authentication device 50 is a device that authenticates an individual using a finger vein pattern image as biometric information, and includes a bus 10, a control unit 11, a light source unit 2, a light control unit 3, an imaging unit 6, an image saving unit 15, and an image composition unit. The unit 16 includes a feature information extraction unit 17, an authentication determination unit 18, and a storage unit 19.

  The bus 10 is a transmission path for each component of the finger vein authentication device 50 to exchange data. The control unit 11 performs overall control of each component of the finger vein authentication device 50. In addition, the control unit 11 performs control so that the state of the light control unit 3 is set to a reflection state or a transmission state according to a region where a finger is imaged. The light source unit 2 irradiates the finger with light. The light control unit 3 includes a plurality of light control units, and each light control unit is set to a reflection state or a transmission state by individually controlling light reflection. The imaging unit 6 converts the scattered light into a finger vein image. The image saving unit 15 temporarily saves the finger vein image converted by the imaging unit 6. The image composition unit 16 composes a plurality of images. Even if there are overlapping image portions between the images, the images are synthesized so as to maintain continuity. The feature information extraction unit 17 extracts individual unique feature information from the captured image.

  The authentication determination unit 18 compares the feature information of a template (described later in detail) registered at the time of registration with the feature information extracted from the finger vein image captured at the time of authentication, thereby authenticating whether or not the user is the person. I do. The storage unit 19 stores information on templates of all persons to be registered, such as feature information extracted from finger vein images captured at the time of registration.

  Here, FIG. 9 shows an example of the data structure of the template.

  The template includes ID 30, feature information 31, central image authentication success count 32, lower left composite image authentication success count 33, and lower right composite image authentication success count 34.

  ID 30 is an identification code assigned to each individual in order to identify the user. The feature information 31 is information obtained by extracting feature points of the shape from the finger vein image captured at the time of registration. The number of successful central image authentications 32 is the number of successful authentications with only the central image. The lower left composite image authentication success count 33 is the number of times authentication is successful by an image obtained by combining the center image and the lower left image. The lower right composite image authentication success count 34 is the number of times authentication has succeeded with an image obtained by combining the center image and the lower right image.

  FIG. 1 is a diagram illustrating a configuration example of an entry / exit management system configured with a finger vein authentication device 50 as a personal authentication device.

  The entry / exit management system is a system that manages entry / exit permission into the room based on the result of identity verification, and includes a finger vein authentication device 50, an entry / exit control device 42, an electric lock 43, and a door 44.

  In the entrance / exit management system, the finger vein authentication device 50 performs authentication with a finger, and the entrance / exit control device 42 controls the unlocking of the electric lock 43 of the door 44 based on the authentication result.

  2 and 3 are diagrams for explaining the imaging of the image of the finger 1 by the finger vein authentication device 50. FIG. 2 shows the finger vein authentication device 50 from the fingertip direction of the finger 1, and FIG. It is a figure. In FIG. 3, the light source unit 2a and the light control units 3La and 3Lb are not shown because they overlap the light source unit 2b and the light control units 3Ra and 3Rb, respectively.

  First, the light source units 2 a and 2 b irradiate the finger 1 with light. The scattered light of the finger 1 irradiated with light is guided to the imaging unit 6 through the dimming units 3c, 3La, 3Lb, 3Ra, and 3Rb, and an image of the finger 1 is captured. At this time, depending on whether the light control units 3c, 3La, 3Lb, 3Ra, and 3Rb are in a reflection state or a transmission state, the image area of the finger 1 to be imaged is divided into three types (center portion, lower right portion, lower left portion). Can be changed. Hereinafter, imaging of an image of each region will be described.

FIG. 4 is a diagram for explaining a case where an image of the center portion of the finger 1 is captured.
The dimming units 3c, 3La, 3Lb, 3Ra, and 3Rb are all in a transmissive state. Scattered light 7 a from the central part passes through the light control unit 3 c and reaches the imaging unit 6. On the other hand, the scattered light 7b from the lower left part and the scattered light 7c from the lower right part do not reach the imaging part 6 because they pass through the light control parts 3La and 3Ra, respectively. Therefore, an image of the central portion of the finger 1 can be obtained by imaging the scattered light 7a that has passed through the light control portion 3c.

  FIG. 5 is a diagram for explaining a case where an image of the lower left part of the finger 1 is captured.

  The light control units 3c, 3La, and 3Lb are in a reflective state, and the light control units 3Ra and 3Rb are in a transmissive state. The scattered light 7a from the central portion does not reach the imaging unit 6 because it is reflected by the light control unit 3c. Scattered light 7b from the lower left part is reflected by the light control units 3La and 3Lb and reaches the imaging unit 6. The scattered light 7c from the lower right does not reach the imaging unit 6 because it passes through the light control units 3Ra and 3Rb. Therefore, an image of the lower left part of the finger 1 can be obtained by imaging the scattered light 7b reflected by the light control units 3La and 3Lb.

  FIG. 6 is a diagram for describing a case where an image of the lower right portion of the finger 1 is captured.

  The dimming units 3c, 3Ra, and 3Rb are in a reflective state, and the dimming units 3La and 3Lb are in a transmissive state. The scattered light 7a from the central portion does not reach the imaging unit 6 because it is reflected by the light control unit 3c. The scattered light 7c from the lower right part is reflected by the light control units 3Ra and 3Rb and reaches the imaging unit 6. The scattered light 7b from the lower left part does not reach the imaging unit 6 because it passes through the light control units 3La and 3Lb. Therefore, an image of the lower right portion of the finger 1 can be obtained by imaging the scattered light 7c reflected by the light control units 3Ra and 3Rb.

  FIG. 10 is a diagram for explaining an operation of registering information related to biometric information by the finger vein authentication device 50.

  First, the light source units 2a and 2b are turned on and light is applied to the finger 1 (S10). The control unit 11 controls the dimming units 3c, 3La, 3Lb, 3Ra, and 3Rb to be set to a reflection state or a transmission state according to three types of imaging regions (center image, lower left image, lower right image) (S11). . The image of the finger vein is captured by the imaging unit 6 (S12). The light sources 2a and 2b are turned off (S13). The captured image is temporarily saved in the image saving unit 15 (S14).

  It is determined whether or not all three types of images, that is, the center image, the lower left image, and the lower right image have been captured (S15). If the imaging of all images has not been completed, the process returns to S10 to capture an image that has not been captured.

  On the other hand, when all of the images have been captured, the center image, the lower left image, and the lower right image are combined by the image combining unit 16 (S16). The feature information extraction unit 17 extracts the feature information 31 from the composite image (S17). Based on the extracted feature information 31, the template is stored in the storage unit 19 (S18). In addition, the central image authentication success count 32, the lower left composite image authentication success count 33, and the lower right composite image authentication success count 34 of the template are stored in the storage unit 19 as 0.

  FIG. 11 is a diagram for explaining an operation of authenticating an individual by the finger vein authentication device 50.

  First, the light sources 2a and 2b are turned on, and light is applied to the finger 1 (S30). The control part 11 controls each light control part (S31). At the time of the first imaging, the states of the light control units 3c, 3La, 3Lb, 3Ra, and 3Rb are set to the reflection state or the transmission state so as to capture the center image. At the time of the second imaging, the lower left composite image authentication success count 33, which is the number of successful authentications in the composite image of the lower left image and the central image in the template, and the successful authentication count in the composite image of the lower right image and the central image. The lower right composite image authentication success count 34 is compared, and as a result of comparison, the states of the light control units 3c, 3La, 3Lb, 3Ra, and 3Rb are reflected or transmitted so that the image with the higher authentication success count is captured. Set to state. At the time of the third imaging, the states of the light control units 3c, 3La, 3Lb, 3Ra, and 3Rb are set to the reflection state or the transmission state so as to capture an image of the remaining area that has not been captured twice. To do. Imaging is performed in the state of each light control unit set in S31. (S32).

  As described above, in the second imaging, since the image of the region with the higher number of successful authentications is captured between the lower left and the lower right, the authentication with the first central image has failed. Even so, the probability of success in the authentication for the second image increases. This is because the finger may be rotated in either direction depending on the habit of the person performing authentication.

  When the imaging is completed, the light sources 2a and 2b are turned off (S33). The captured image is temporarily saved in the image saving unit 15 (S34). At the time of the second or third imaging, the center image captured at the first time and the image captured at the second or third time are combined by the image combining unit 16. Note that the image is not synthesized at the first imaging (S35). Feature information is extracted from the composite image by the feature information extraction unit 17 (S36). A template is read from the storage unit 19 (S37). The feature information extracted at the time of authentication and the feature information 31 in the template are compared and authenticated by the authentication determination unit 18 (S38).

  It is determined whether or not the authentication is successful (S39). If the authentication is successful, it is accepted as the principal, and processing suitable for each application is performed (S40). For example, in the case of an entrance / exit management system, the door key is unlocked, and in the case of an ATM (Automatic Teller Machine) installed in a bank or the like, the process proceeds to transaction processing.

  Of the template central image authentication success count 32, the lower left composite image authentication success count 33, and the lower right composite image authentication success count 34, the success count is added to the one corresponding to the current authentication success, and the storage unit The content of 19 is updated (S41).

  If the authentication is not successful in S39, the process proceeds to S50, and if all three types of images have not been captured, the process returns to S30 and the next image is captured. Here, in the case of the second imaging, the area to be imaged is an area corresponding to a template having a higher success number of the lower left composite image authentication success count 33 and the lower right composite image authentication success count 34 of the template. If the authentication is not successful even after the third imaging, the authentication is finally rejected and a rejection process is performed for each application (S51).

  FIG. 7 is a diagram for explaining a case where authentication is performed with the finger 1 rotated in the A direction. Here, at the time of registration, it is assumed that the finger 1 is imaged in a normal state where the finger 1 is not rotated as shown in FIGS. 4, 5, and 6.

  At the time of authentication, only the central image obtained by the first image pickup has a small area overlapping with the image picked up at the time of registration, and even if authentication fails, the right image obtained by the second or third image pickup can be obtained. By further adding the lower image, the overlapping area becomes larger than the image at the time of registration, so that authentication can be successful.

  As described above, even when the finger 1 is placed on the finger vein authentication device 50 in a rotated state, by providing the light control unit according to the present embodiment, not only the front surface (corresponding to the central image) of the finger 1 but also the side surface. Since authentication is performed by capturing images of a plurality of regions including (lower right image and lower left image), authentication performance can be improved.

  With the above configuration, by controlling each dimming unit to be reflective or transmissive, it is possible to capture images of regions at multiple positions of the finger, and even when the finger is placed in a rotated state, There is an effect that the ratio of the area where the image and the image at the time of authentication do not become small, and the authentication performance does not deteriorate.

  In addition, in the prior art, two sets of the imaging unit 6 are necessary. However, in the present embodiment, since only one set is configured, the scale of the apparatus can be reduced accordingly. Further, since the imaging unit 6 is not configured to move as in the prior art, the time required for the movement becomes unnecessary, and the processing time required for authentication can be shortened accordingly.

  In this embodiment, an example of a personal authentication device using a finger vein is described, but a personal authentication device using a fingerprint may be used.

  In the present embodiment, the storage unit 19 is connected to the bus 10 in the personal authentication device and stores the templates of all registered persons. However, as a template storage method, one person is stored in the IC card. A template may be stored, and a template may be acquired from a remote database by communication.

  In the present embodiment, images of up to three types of regions are captured, but the number of light control units may be reduced so as to capture images of up to two types of regions.

  Further, in this embodiment, the light source unit is arranged near the lower side of the finger. However, the light source unit may be arranged directly above the finger. In some cases, both light sources may be turned on, the lower left imaging unit may be lit on the left side, and the lower right imaging unit may be lit only on the right side.

  Furthermore, in the present embodiment, imaging is performed a maximum of three times at the time of authentication. However, in an application where it is desired to shorten the authentication processing time, the authentication may be completed by capturing the central image only once. This is because a template is already created with an image obtained by synthesizing three areas at the time of registration, and therefore, the probability of success even with authentication of only the central image is high.

  The present invention is not limited to the specifically disclosed embodiments, and various modifications and changes can be made without departing from the scope of the claims.

The figure which shows the structural example of the entrance / exit management system by a present Example. The figure for demonstrating imaging of the image of a finger (the 1). The figure for demonstrating imaging of the image of a finger (the 2). The figure for demonstrating imaging of the area | region of a center part. The figure for demonstrating imaging of the area | region of the lower left. The figure for demonstrating imaging of the area | region of a lower right part. The figure for demonstrating the authentication in the state which the finger rotated. The block diagram which shows the structural example of the finger vein authentication apparatus by a present Example. The figure which shows the structural example of the data of a template. The figure for demonstrating operation which registers biometric information. The figure for demonstrating operation of authentication.

Explanation of symbols

1: finger, 2, 2a, 2b: light source unit, 3, 3c, 3La, 3Lb, 3Ra, 3Rb: dimming unit, 6: imaging unit, 10: bus, 11: control unit, 15: image retracting unit, 16 : Image composition unit, 17: feature information extraction unit, 18: authentication determination unit, 19: storage unit, 50: finger vein authentication device.

Claims (2)

An irradiation unit that irradiates light on a finger set in a predetermined unit, and an imaging unit that captures an image of the finger with light reflected from the finger by the light irradiated by the irradiation unit. In the personal authentication device for authenticating whether or not the person is based on the image that has been
A plurality of light control units that reflect or transmit light irradiated by the irradiation unit;
Switching control means for switching the plurality of light control units to a reflective or transmissive state according to the position of a finger to be imaged;
A personal authentication device for authenticating whether the user is the person or not based on the image picked up by the light obtained through the light control unit switched to the reflection or transmission state by the switching control means . A storage unit that stores the number of successful authentications associated with the image according to the position of the finger;
2. The personal authentication apparatus according to claim 1, wherein authentication is performed using the image corresponding to the position of a finger based on the number of successes stored in the storage unit.

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